Avaliação da capacidade de remoção de azul de metileno utilizando hematita e pó de rocha basaltica como adsorvente

Abstract

In this work, the removal of methylene blue dye was studied using hematite nanoparticles and basaltic rock powder as adsorbents. Both adsorbents were characterized using techniques such as: X-ray diffraction (DRX), Fourier transform infrared spectroscopy (FTIR) and zero charge point (pH (PCZ). The hematite nanoparticle was also characterized based on by scanning electron microscopy (SEM). The basaltic rock powder, in turn, was characterized based on X-ray fluorescence, loss on fire and optical emission spectrometry (ICP -OES) analyses. characterization it was possible to define parameters to evaluate the dye removal capacity at different pH values. from the mining industry. For the X-ray diffraction analysis, it was possible to observe characteristic peaks of the hematite crystalline phase in the hematite nanoparticle sample, also from the mining industry. It was possible to observe the presence of pyroxene, plagioclase, and quartz in the basaltic rock dust sample. In the FTIR analysis, it was possible to observe the presence of characteristic peaks of iron in both samples, in addition to the presence of silicon in the basaltic rock powder sample. Based on X-ray fluorescence and fire loss analysis, contents of 51.1% of silicon dioxide, 15.2% of hematite and 13.2% of hematite were obtained in the basaltic rock powder sample. The ICP-OES analysis for the basaltic rock dust returned results within the specification described by CONAMA resolution 420/2008 for heavy metals. For the point of zero charge, mean values of 6.5 were found for the basaltic rock powder and 5.5 for the hematite nanoparticle. The research brought satisfactory results in terms of dye removal capacity, with average results of 1.73 mg.g-1 for hematite and 2.08 mg.g-1 for basaltic rock powder. The superior removal capacity from basaltic rock dust may justified to the presence of alumina in the composition of this material, thus having a greater number of active sites where the dye can be adsorbed. The present research opens doors for new studies using basaltic rock powder.